package 剑指Offer专项突破;

/**
 * @Author zhang lei
 * @Date 2021-12-08 12:52
 * @Description  动态规划
 */
public class Algo098 {
    /**
     * m x n 方格，到达m,n的路径个数
     * @param m
     * @param n
     * @return
     */
    public static int uniquePaths(int m, int n) {
        int[][] dp = new int[m][n];

        for (int i = 0; i < m; i++) {
            dp[i][0] = 1;
        }
        for (int i = 0; i < n; i++) {
            dp[0][i] = 1;
        }

        for (int i = 1; i < m; i++) {
            for (int j = 1; j < n; j++) {
                dp[i][j] = dp[i-1][j] + dp[i][j-1];
            }
        }
        return dp[m-1][n-1];
    }


    /**
     * algo99 下降最小路径和
     * @param grid
     * @return
     */
    public static int minPathSum(int[][] grid) {
        int m = grid.length;
        int n = grid[0].length;
        int[][] dp = new int[m][n];
        dp[0][0] = grid[0][0];
        for (int i = 1; i < m; i++) {
            dp[i][0] = grid[i][0] + dp[i-1][0];
        }
        for (int i = 1; i < n; i++) {
            dp[0][i] = grid[0][i] + dp[0][i-1];
        }

        for (int i = 1; i < m; i++) {
            for (int j = 1; j < n; j++) {
                dp[i][j] = Math.min(dp[i-1][j], dp[i][j-1]) + grid[i][j];
            }
        }
        return dp[m-1][n-1];
    }

    public static void main(String[] args) {
//        System.out.println(uniquePaths(3, 3));
        System.out.println(getNumer());
    }

    private static int getNumer() {
        int count = 0;
        return ++count;
    }


}
